We need artificial gravity pronto.

mbkennel

bobs_uruncle
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No, not missing anything but the actual numbers and I don't really feel like working them out. However, if you are moving a ship of 50k kg's at 99.99% C that will take a specific amount of energy to accelerate and then maintain that speed. If you come upon a mass of 50kg and have to force it our of the way, that will also take a specific amount of energy because of the relativistic speed at which you are approaching the object and the simple fact that it has to be moved, quite possibly at right angles to the direction you are traveling. It wouldn't obviously take as much energy to move the object at 0.1% of your ships mass as it would to change the ship's direction, but it would probably take something in the range of 0.2 to 0.4% of the energy being used by the ship to travel through space for both deflection and course correction (action and reaction).

Cheers - Dave

Agreed, no argument. The original claim was more like "would take more energy than the Universe".

Depending on your final speed close to C, the energy required to move objects out of the way could easily exceed the total energy of the universe.

edit on 19-3-2014 by mbkennel because: (no reason given)

Actually, I can't remember the actual mass required to move at C in order to exceed the total energy of the universe, but it was not very large if I remember right. With Einstein's expression of E=mc^2, you could work it out. But since there are 10^80 (roughly) particles in the visible universe that would provide a baseline to work against.

The Gaurdian's cute little article

It obviously doesn't explain it all, but if mass increases due to energy input while approaching C and the length of your ship reduces to that of a literal 2 dimension plane... I think we have a problem Houston. Eventually your mass would become greater than the total mass of the universe divided by C^2 and then that dog don't hunt here.

Cheers - Dave

I think we are just to primitive in technology, politics & economy to have artificial gravity anytime soon. I brought it up because of all the recent interest in crewed interplanetary travel and crewed beyond L.E.O journeys. Weightlessness exposure to astronauts presents a big a health risk as radiation exposure for long term space travel. you could go blind, loose muscle mass & bone strength, and it greatly effects the immune system & could alter blood chemistry. There's also a risk of becoming paralyzed because of exposure to weightlessness. I know NASA and other space agencies aren't hungry for artificial gravity but they should be if they want a place in the solar system and maybe even beyond.